The present invention relates generally to plasma treatment chamber system for treating cables, wires, filaments, strands, or the like, and more particularly to a dual electrode plasma treatment chamber system which effectively renders the system electrically safe for operator personnel.
Plasma reactors or plasma generators are of course well-known in the art. It is also well-known in the art to utilize such plasma reactors or plasma generators to treat cables, wires, filaments, strands, or the like for various purposes or objectives in connection with further usage or processing of such cables, wires, filaments, strands, or the like. Plasma reactors or plasma generators which are utilized for such purposes or objectives are exemplified within U.S. Pat. No. 5,972,160 which issued to Straemke on Oct. 26, 1999, U.S. Pat. No. 5,254,372 which issued to Nichols on Oct. 19, 1993, U.S. Pat. Nos. 4,550,578 and 4,466,258 which issued to Sando et al. on Nov. 5, 1985 and Aug. 21, 1984, respectively, and U.S. Pat. Nos. 3,872,278 and 3,780,255 which issued to Boom on Mar. 18, 1975 and Dec. 18, 1973, respectively.
In addition to the aforenoted patents and the various cable, wire, filament, or strand processing systems disclosed therein, a commercially available cable or wire plasma treatment chamber system is disclosed within FIG. 1. In accordance with such a PRIOR ART system, it is seen that the PRIOR ART system is of the single electrode type. More particularly, the PRIOR ART cable or wire plasma treatment chamber system is generally indicated by the reference character 10 and is seen to comprise an insulated enclosure 12 within which a cylindrically configured tubular plasma treatment chamber 14 is disposed. A wire to be treated is disclosed at 16 and it is seen that the wire 16 is in effect adapted to be disposed coaxially within the plasma treatment chamber 14. A high voltage generator comprises, for example, a transformer 18 which includes a primary winding stage 20 and a secondary winding stage 22. A first end of the secondary winding stage 22 of the high voltage generator transformer 18 is electrically connected to an electrode 24 of the plasma treatment chamber 14 by means of a first electrical conductor wire 26, and the second end of the secondary winding stage 22 of the high voltage generator transformer 18 is electrically connected to ground as at 28 by means of a second electrical conductor wire 30. The primary winding stage 20 of the high voltage generator transformer 18 is also electrically connected to ground as at 32 by means of a third electrical conductor wire 34, and the wire 16 to be treated is also grounded as at 36. It is therefore apparent that in accordance with such a single electrode plasma treatment chamber system 10, the return current for the plasma, shown by the arrows C, has to flow by means of the wire 16 outside of the plasma chamber 14 which is in effect electrically connected to the secondary winding stage 22 of the high voltage generator transformer 18 through means of a ground path. This is a very dangerous situation or condition in view of the fact that this arrangement or structural assembly presents potentially lethal voltage levels to the wire 16 to be treated. More particularly, if the operator is grounded and touches the treated wire 16 while the plasma chamber 14 is in operation, the operator completes the high voltage series circuit from the treated wire 16 to ground. In view of the additional fact that the primary winding stage 20 of the high voltage generator transformer 18 is electrically connected to a conventional power source, while the secondary winding stage 22 is characterized by means of a voltage level of, for example, 30,000V, the voltage that would be present upon the wire 16, which is derived from the plasma within the chamber 14, would be 1.6 kV peak-to-peak with an RMS value of approximately 538V. The source impedance is also noted as being low enough to produce 181 mA RMS of current. These levels are well above acceptable amplitudes, such as, for example, 30 mA that can Cause respiratory paralysis, or 75 mA that can cause heart fibrillation.
The prior art has sought to rectify the aforenoted operational difficulties, drawbacks, or disadvantages by in effect, for example, incorporating, adding, or impressing capacitive and inductive loading within, to, or upon the wire to be treated. Such solutions, however, have not in fact proven to be adequate or viable in view of the fact that such implementations have still permitted enough voltage to remain upon the treated wire to result in shocking the operator. In addition, different types and sizes of wires require different capacitive and inductive levels, values, or loads to be utilized in connection with the particularly sized or types of wires in order to achieve the desired loading and reduction in the voltage and current levels or values. These solutions therefore entail considerable added expenses, they require additional setup time and procedures, and they result in substantial operational downtime.
A need therefore exists in the art for a new and improved plasma treatment chamber system for treating wires wherein the system is rendered electrically safe for operator personnel while overcoming the various operational drawbacks or disadvantages characteristic of the prior art systems in that additional capacitive or inductive loading devices are not in fact required, and wherein further, time-consuming setup arrangements, tailored for each different type or size of wire being treated, are also rendered unnecessary.
Accordingly, it is an object of the present invention to provide a new and improved plasma treatment chamber system for treating wires.
Another object of the present invention is to provide a new and improved plasma treatment chamber system for treating wires which overcomes the various operational and procedural disadvantages or drawbacks characteristic of the prior art.
An additional object of the present invention is to provide a new and improved plasma treatment chamber system for treating wires wherein the system is rendered electrically safe for operator personnel.
A further object of the present invention is to provide a new and improved plasma treatment chamber system for treating wires wherein the system is operable with all types and sizes of wires without requiring the additional implementation or incorporation of auxiliary capacitive or inductive loading devices.
The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved plasma treatment chamber system for treating wires wherein, in lieu of the single electrode system characteristic of the prior art, the system of the present invention comprises a dual electrode plasma treatment chamber system. More particularly, a second plasma chamber is disposed within the insulated enclosure, and the first end of the secondary winding stage of the high voltage generator transformer is electrically connected to the electrode of the first plasma treatment chamber. However, in accordance with the unique and novel arrangement and electrical connections defined between first and second plasma treatment chambers and the secondary winding stage of the high voltage generator transformer, and more particularly, in lieu of the second end of the secondary winding stage of the high voltage generator transformer being electrically connected to ground, the second end of the secondary winding stage of the high voltage generator transformer is electrically connected to the electrode of the second plasma treatment chamber.
Equal and opposite voltages, that is, voltage levels which are equal in amplitude but opposite in phase, or in other words, 180xc2x0 out-of-phase with respect to each other, are therefore applied to each electrode. As a result of such an arrangement or disposition of the dual plasma treatment chambers and the electrical connection of their respective electrodes to the secondary winding stage of the high voltage generator transformer, the loading effects of the two out-of-phase electrodes effectively cancel each other whereby substantially all of the circulating electrical current is contained within the insulated enclosure while only voltage levels, which are acceptably low from a personnel safety point of view, are effectively impressed or present upon, for example, that portion of the wire to be treated which is disposed externally of the insulated enclosure, and yet, the voltage levels are obviously nevertheless sufficient enough within each plasma treatment chamber to permit the desired surface treatment of the wire to still be achieved.